Thermally actuated power aerial device



msoms W. W. WOOD THERMALLY ACTUA'IED POWER AERIAL DEVICE June 22, 1965 2Sheets-Sheet 1.

Filed Feb. 13, 1961 a ll INVENTOR. gVOQD AT TORNEY June 22, 1965 w. w.woon 3,190,033

THERMALLY ACTUATED POWER AERIAL DEVICE Filed Feb. 13, 1961 2Sheets-Sheet 2 FIG. 7

INVENTOR.

WILBURN W. WOOD ATTORNEY United States Patent 3,190,933 THERWALLYAQTUATED NEWER AERIAL DlEWiIE Wilhurn W. Wood, 79 East Road, Tacoma,Wash. Filed Feb. 13, 1961, Ser. No. 83,991 Claims. (Ci. 4574) Thisinvention relates to a thermally actuated power device and although theprinciples thereof may have various applications one particularapplication thereof, and as illustrated herein, is in a toy missile.

An important object of the present invention is to provide a thermallyactuated power device having a novel power drive system, and moreparticularly one employing a pressure chamber containing a thermallysensitive, expandable material adapted to rupture an end wall of thechamber for producing a thrust.

It is another object of the present invention to provide in combinationa pressure chamber containing a thermally sensitive, expandable materialadapted to rupture an end wall of the chamber for producing a thrustupon being subjected to heat, and means for producing such heat.

Another object is to provide a device of the type described havingimproved wall structure which is adapted to rupture upon being subjectedto a predetermined pressure and which upon rupturing merely opens into apuncture-like configuration rather than in any case permitting fragmentsto break loose.

Another object is to provide a device of the type de scribed having animproved thrust tube construction.

Another object is to provide a device of the type described in the formof a toy missile having novel means for supporting and launching thesame.

Still another object is to provide a novel combination of toy missile,launching pad and circuit means for actuating power drive means of themissile.

Briefly stated, the illustrated toy missile which incorporates thefeatures of the present invention comprises a body member having achamber adapted to contain a thermally sensitive expandable materialwhich when heated a selected amount produces sufficient pressure torupture a weakened wall portion of the chamber, thus producing a thrustto drive the missile. Also forming a part of the present invention aremeans to heat the chamber and means for supporting the missile forlaunching. Such heating and supporting means comprises a launching padin which is incorporated a heating element,

a source of potential, and a switch for closing the circuit between thesource of potential and the heating element.

The invention will be better understood and other objects thereof willbecome apparent from the accompanying specification and claimsconsidered together with the accompanying drawings, wherein likenumerals of reference indicate like parts, and wherein:

FIG. 1 is a perspective view of a toy missile incorporating the featuresof the present invention;

FIG. 2 is an enlarged fragmentary sectional view of a joint structure ofthe weakened wall portion of the body member chamber;

FIG. 3 is a perspective view, slightly enlarged, ot the weakened wallportion of the body member chamber, shown apart from other structure,after rupture thereof;

FIG. 4 is a perspective view of one form of a launching pad, togetherwith a source of potential and switch;

FIG. 5 is an elevational view of a missile seated on the launching padof FIG. 4;

FIG. 6 is a perspective view of another form of launching mechanism;

FIG. 7 is a side elevational view of a cradle incorporated in theembodiment of FIG. 6 for supporting a missile;

FIG. 8 is a top plan view of the cradle;

FIG. 9 is a front edge view of said cradle; and

FIG. 10 is a sectional view taken on the line 1tl-1tl of FIG. 8.

Referring now particularly to the drawings and first to FIG. 1, thepresent thermally actuated. power device comprises a hollow tubular bodymember 11) which for the purposes of illustrating one purpose thereofmay be formed in the shape of a toy missile, one end 12 of the body it?being closed and the opposite end 14 beingopen. Mounted intermediate thetwo ends is a transverse sealing member such as a diaphragm 16 which hasan integral connection around its peripheral edge with body 1% to forman upper air-tight chamber 18.

The joint between the diaphragm 16 and the tubular body it may compriseany suitable construction. In this regard and as shown in FIG. 2, thebody 16 comprises an upper gas pressure chamber 10a and a lower emptythrust chamber lilb. The juncture of the diaphragm l6 therewithcomprises a rolled joint wherein the outer edges of the diaphragm arerolled and turned back into adjacent edges of the body portions andcompressed tightly to provide an air-tight pressure connection.

Diaphragm 1c is formed of a plate material which will withstand apressure less than the other confining walls of chamber 18 whereby whenthe pressure in the chamber builds up to a certain point the diaphragmwill rupture. The material from which the diaphragm is made preferablycomprises thin metal. Such diaphragm is provided with radially extendingweakened portions 22 whereby when the diaphragm fails as a result ofpressure in the chamber 18 it will merely assume a punctured-likecondition at its weakened portion rather than in any case permittingfragments thereof to break loose. The pattern of the weakened area 22before rupture is illustrated in FIG. 1, and the condition of thediaphragm after rupture thereof is illustrated in FIG. 3.

The body portion lit preferably is formed of a heat conducting materialso that it and chamber 18 will readily assume the temperature ofsurrounding conditions. The diaphragm to also preferably is formed of aheat conducting metal whereby heat of. adiacent areas may readily betransmitted to the chamber 18.

It is to be understood that other forms of weakening lines or thinnedareas may be provided to accomplish the desired results which are,first, to cause the diaphragm to fail prior to the other walls of thebody member and, second, to rupture almot instantaneously to produce adriving thrustfrom pressured discharge of the contents of chamber 18.

Pressure in the chamber 18 is developed by a thermally sensitivematerial 24 which upon being heated converts to a gaseous form and uponreaching a selected temperature will have produced a sufiicient pressureto rupture the diaphragm. As an example of the material used in thechamber 13, a material of low boiling point such as a fiuorinatedhydrocarbon may be used which at normal temperature exists in liquidform and which upon being heated immediately converts to a gas toaccomplish the desired result. Thus, it is desirable that a material 2dbe used which remains in liquid form at room temperature or anytemperature thereabove which normally would be encountered prior to useof the toy, but which would be converted to gaseous form at highertemperatures.

The escape of the gas from chamber 18, upon failure of diaphragm 16,will produce a thrust sufficient to lift the missile a considerabledistance into the air. The lower portion 12% of the body lltl has arestricted throat or Venturi 3d. This throat as one purpose restrictsslightly the discharge of pressure from chamber 18 to prolong the thrustfrom the open end of the missile. The present thermally actuated powerdevice when used as a toy missile is provided with fins 32.

Also forming a part of the present invention is a support or launchingpad for the toy missile which in a preferred construction is adapted tohold the missile in a starting position as well as to produce heatnecessary to convert the thermally sensitive material 24 in chamber togas. One form of launching pad and heating means is shown in FIG. 5. Inthis embodiment there is employed a base 3-6 and an upright standard 38adapted to receive thereover the lower portion of the missile as shownin FIG. 5. Incorporated in the standard 3% ad jacent the upper endthereof is a heating element 40. The standard is of a predeterminedlength relative to the length of the lower portion Nb of body lit thatwhen the missile is seated on the standard the heating element 4 isdisposed closely adjacent the under surface of diaphragm 16. Therefore,when heat is applied to the element ll) the chamber 13 is heated rapidlyand the gaseous charge is created therein.

Heating element 40 is connected to wires 42, 4-4, which together with awire 45 form a circuit including a source of potential 46 and a switchmechanism 47. The source of potential 4-6 may comprise one or more drycells mounted in a metal holder 455 or of course may comprise analternating current source. The holder in cross section ischannel-shaped and has at one end thereof a spring finger St! forholding the batteries in the holder. The forward end of the holdercomprises an integral upright front metal wall 52 having a bifurcatedportion 54- for receiving an insert 56 of insulating material supportingcentrally thereof a metal eyelet 58 engageable by the top terminal ofthe forward battery. Eyelet 58- is held spaced from metal wall 52 by theinsert 56. As apparent in FIG. 5 wire is connected to eyelet 58 and wire44 is connected to front wall 52 to complete a circuit through thebatteries and holder.

Switch 47 is of a structure to serve both to close the circuit betweenthe source of potential and the heating element and to limit circuitclosure time for each operation. The switch comprises a housing 61having internal shoulders 62 for supporting a curved leaf spring contactmember 64 engaged by a push button 66 and connected to wire 45. Spring64 is adapted to return push button as to an outer position whenreleased. Disposed adjacent contact member 6- and adapted to be engagedthereby upon pushing button 66 inwardly is a bimetallic contact 68supported at one end and connected to Wire 42. It will be apparent thatupon pressing button 66 the switch is closed and current is supplied toheating element 40 to heat chamber 18 of a missile.

Bimetallic contact 68 is arranged to disengage itself from contact 64and thus open the circuit after engagement with the latter contact for aselected length of time. Thus, upon closing the circuit by pushingbutton 66, the contact 68 will remain in the circuit until thedifferential of expansion of the elements thereof causes it to releaseitself, such circuit closure time being for example around three secondsor a preselected time such as to allow heating of the element as to adesired temperature. Such switch action prevents a drain on thebatteries in the event the button as is held down.

PIGS. 6l0 illustrate a second form of launcher for the missile. Thisembodiment comprises a trough-shaped holder '74. This holder has a pairof integral depending apertured cars '76 supported on a horizontal bolt'78 in a base member 80. Bolt 78 is threaded at one end to receive aWing nut $2 which is adapted to be adjusted to a position permittingadjustment of the holder '74 or a set position. One of the ears in has apointer or index mark 84 and the base 38 has indicia 86 for the purposeof setting or indicating the inclination of the holder.

Trough '74 is provided with an elongated heating element connected tocircuit wires 42a and 44a. Preferably, the trough comprises a hollowbody portion, as best seen in FIG. 10, and the heating element is housedtherein. It is to be understood, however, that the heating element maylie on the upper or lower surface thereof if desired.

In the FIG. 6 embodiment, the missile lies in the trough 74 and upon theheatin of element 96, the body of said missile is heated to convert thethermally sensitive mate rial 24 to gas. By adjustment of the troughrelative to thehorizontal, the missile can be directed at the desiredangle.

The body portion it? may also serve as a fire detecting device sincewhen the diaphragm l6 fails due to a heating of chamber 13 it produces aloud report. For this purpose, the body lltl may be locatedstrategically around the home or other building.

It is to be understood that the forms of my invention herein shown anddescribed are to be taken as preferred.

examples of the same and that various other changes in the shape, sizeand arrangement of parts may be resorted to without departing from thespirit of my invention or the scope of the subjoined claims.

Having thus described my invention, I claim:

1. A thermally actuated power device comprising a tubular body memberclosed at one end and open at the other, a rupturable transverse sealingmember in said body member intermediate the ends thereof for forming aclosed pressure chamber with said closed end and an empty thrust chamberwith said open end, said sealing member being arranged to openinstantaneously upon being subjected to a selected gas pressure,heat-actuable gas generating means disposed interiorly of said pressurechamber and being adapted to pressurize said pressure chamber andrupture instantaneously said sealing member to produce a gas powerthrust through said thrust chamber and said open end of the body member,and heating means disposed exteriorly of said pressure chamber to heatthe same and actuate said gas generating means.

2. The thermally actuated power device of claim 1 wherein saidtransverse sealing member comprises a dia phragm fixedly connectedaround the edge thereof to said body portion and having a weakened areainwardly from said edge for instantaneous puncture of said diaphragmupon a selected gas pressure being developed in said pressure chamber.

3. The thermally actuated power device of claim 1 including holdingmeans for said device, said heating means being incorporated in saidholding means and being disposed closely adjacent said pressure chamberto heat the same.

4. The thermally actuated power device of claim 3 wherein said holdingmeans comprises a horizontal base, and an upright standard arranged toproject into said thrust chamber.

5. The thermally actuated power device of claim 3 wherein said holdingmeans comprises a base, and a trough-shaped member in which said tubularbody member is adapted to lie.

References Cited by the Examiner UNITED STATES PATENTS 556,058 3/96 Huey12411 2,588,184 3/52 Walsh 4674 2,640,417 6/53 Bjork et a1. 102-492,645,999 7/53 Bogard 102--49 6 2,683,330 7/ 54 Taylor 46-76 2,724,23711/55 Hickman 4674 2,918,751 12/59 Johnson 4674 FOREIGN PATENTS 164,2968/58 Sweden. 405,645 1/34 Great Britain.

RICHARD C. PINKHAM, Primary Examiner.

DELBERT B. LOWE, JOHN M. HORAN, Examiners.

1. A THERMALLY ACTUATED POWER DEVICE COMPRISING A TUBULAR BODY MEMBERCLOSED AT ONE END AND OPEN AT THE OTHER, RUPTURABLE TRANSVERSE SEALINGMEMBER IN SAID BODY MEMBER INTERMEDIATE THE ENDS THEREOF FOR FORMING ACLOSED PRESSURE CHAMBER WITH SAID CLOSED END AND AN EMPTY THRUST CHAMBERWITH SAID OPEN END, SAID SEALING MEMBER BEING ARRANGED TO OPENINSTANTANEOUSLY UPON BEING SUBJECTED TO A SELECTED GAS PRESSURE,HEAT-ACTUABLE GAS GENERATING MEANS DISPOSED INTERIORLY OF SAID PRESSURECHAMBER AND BEING ADAPTED TO PRESSURIZE SAID PRESSURE CHAMBER ANDRUPTURE INSTANTANEOUSLY SAID SEALING MEMBER TO PRODUCE A GAS POWERTHRUST THROUGH SAID THRUST CHAMBER AND SAID OPEN END OF THE BODY MEMBER,AND HEATING MEANS DISPOSED EXTERIORLY OF SAID PRESSURE CHAMBER TO HEATTHE SAME AND ACTUATE SAID GAS GENERATING MEANS.